#region License

/* Copyright (c) 2006 Leslie Sanford
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy 
 * of this software and associated documentation files (the "Software"), to 
 * deal in the Software without restriction, including without limitation the 
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 
 * sell copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
 * THE SOFTWARE.
 */

#endregion

#region Contact

/*
 * Leslie Sanford
 * Email: jabberdabber@hotmail.com
 */

#endregion

using System;
using System.Diagnostics;

namespace TrafficLightDemo
{
    sealed partial class DelegateScheduler
	{
		private sealed class Task : IComparable
		{
			// The number of times left to invoke the delegate associated with this Task.
			private int count;

			// The interval between delegate invocation.
			private readonly int millisecondsTimeout;

			// The delegate to invoke.
			private readonly Delegate method;

			// The arguments to pass to the delegate when it is invoked.
			private readonly object[] args;

			// The time for the next timeout;
			private DateTime nextTimeout;

			public Task(
				int count,
				int millisecondsTimeout,
				Delegate method,
				object[] args)
			{
				this.count = count;
				this.millisecondsTimeout = millisecondsTimeout;
				this.method = method;
				this.args = args;

				ResetNextTimeout();
			}

			public void ResetNextTimeout()
			{
				nextTimeout = DateTime.Now.AddMilliseconds(MillisecondsTimeout);
			}

			public object Invoke(DateTime signalTime)
			{
				Debug.Assert(count == Infinite || count > 0);

				object returnValue = method.DynamicInvoke(args);

				if (count == Infinite)
				{
					nextTimeout = nextTimeout.AddMilliseconds(MillisecondsTimeout);
				}
				else
				{
					count--;

					if (count > 0)
					{
						nextTimeout = nextTimeout.AddMilliseconds(MillisecondsTimeout);
					}
				}

				return returnValue;
			}

			public object[] GetArgs()
			{
				return args;
			}

			public DateTime NextTimeout
			{
				get { return nextTimeout; }
			}

			public int Count
			{
				get { return count; }
			}

			public Delegate Method
			{
				get { return method; }
			}

			public int MillisecondsTimeout
			{
				get { return millisecondsTimeout; }
			}

			#region IComparable Members

			public int CompareTo(object obj)
			{
				Task t = obj as Task;

				if (t == null)
				{
					throw new ArgumentException("obj is not the same type as this instance.");
				}

				return -nextTimeout.CompareTo(t.nextTimeout);
			}

			#endregion
		}
	}
}